<div class="gallery">
  <img src="https://picsum.photos/id/433/600/400" alt="A Bear">
  <img src="https://picsum.photos/id/582/600/400" alt="A wolf">
  <img src="https://picsum.photos/id/1074/600/400" alt="A lioness">
  <img src="https://picsum.photos/id/659/600/400" alt="A kind wolf">
  <img src="https://picsum.photos/id/593/600/400" alt="A Tiger">
</div>

<div class="gallery slanted">
  <img src="https://picsum.photos/id/433/600/400" alt="A Bear">
  <img src="https://picsum.photos/id/582/600/400" alt="A wolf">
  <img src="https://picsum.photos/id/1074/600/400" alt="A lioness">
  <img src="https://picsum.photos/id/659/600/400" alt="A kind wolf">
  <img src="https://picsum.photos/id/593/600/400" alt="A Tiger">
</div>

<div class="gallery zig-zag">
  <img src="https://picsum.photos/id/433/600/400" alt="A Bear">
  <img src="https://picsum.photos/id/582/600/400" alt="A wolf">
  <img src="https://picsum.photos/id/1074/600/400" alt="A lioness">
  <img src="https://picsum.photos/id/659/600/400" alt="A kind wolf">
  <img src="https://picsum.photos/id/593/600/400" alt="A Tiger">
</div>

<div class="gallery rounded">
  <img src="https://picsum.photos/id/433/600/400" alt="A Bear">
  <img src="https://picsum.photos/id/582/600/400" alt="A wolf">
  <img src="https://picsum.photos/id/1074/600/400" alt="A lioness">
  <img src="https://picsum.photos/id/659/600/400" alt="A kind wolf">
  <img src="https://picsum.photos/id/593/600/400" alt="A Tiger">
</div>

.gallery {
  --s: 30px;
  --g: 8px;
  
  display: grid;
  height: 300px;
  margin: 20px 0;
  gap: var(--g);
  grid-auto-flow: column;
  place-items: center;
}
.gallery > img {
  width: 0;
  height: 0;
  min-width: 100%;
  min-height: 100%;
  -webkit-mask: var(--mask);
          mask: var(--mask);
  object-fit: cover;
  cursor: pointer;
  transition: .5s;
}
.gallery > img:first-child {
  place-self: start;
}
.gallery > img:last-child {
  place-self: end;
}
.gallery > img:hover {
  width: 15vw; 
}

:is(.slanted,.zig-zag,.rounded) > img {
  min-width: calc(100% + var(--s));
}
:is(.slanted,.zig-zag,.rounded) > img:first-child,
:is(.slanted,.zig-zag,.rounded) > img:last-child {
  min-width: calc(100% + var(--s)/2);
}

/* slanted gallery */
.slanted > img {
  clip-path: polygon(var(--s) 0,100% 0,calc(100% - var(--s)) 100%,0 100%);
}
.slanted > img:first-child {
  clip-path: polygon(0 0,100% 0,calc(100% - var(--s)) 100%,0 100%);
}
.slanted > img:last-child {
  clip-path: polygon(var(--s) 0,100% 0,100% 100%,0 100%);
}

/* zig-zag gallery */
.zig-zag > img {
  --mask: 
    conic-gradient(from -135deg at right,#0000,#000 1deg 89deg,#0000 90deg) 
      100% calc(50% + var(--_p,0%))/51% calc(2*var(--s)) repeat-y,
    conic-gradient(from   45deg at left ,#0000,#000 1deg 89deg,#0000 90deg) 
        0% calc(50% + var(--_p,0%))/51% calc(2*var(--s)) repeat-y;
}
.zig-zag > img:nth-child(odd) {
  --_p: var(--s);
}
.zig-zag > img:first-child {
  --mask: 
    conic-gradient(from -135deg at right,#0000,#000 1deg 89deg,#0000 90deg) 
      0 calc(50% + var(--_p,0%))/100% calc(2*var(--s));
}
.zig-zag > img:last-child {
  --mask: 
    conic-gradient(from   45deg at left ,#0000,#000 1deg 89deg,#0000 90deg) 
       0 calc(50% + var(--_p,0%)) /100% calc(2*var(--s));
}
/* rounded gallery */
.rounded {gap: 0}
.rounded > img {
  --mask: 
  linear-gradient(-90deg,#0000 calc(2*var(--s)),#000 0) var(--s),
  radial-gradient(var(--s),#000 98%,#0000) 50%/calc(2*var(--s)) calc(1.8*var(--s)) space repeat;
}
.rounded > img:nth-child(odd) {
  --mask: 
  radial-gradient(calc(var(--s) + var(--g)) at calc(var(--s) + var(--g)) 50%,#0000 98% ,#000 ) calc(-1*(var(--s) + var(--g)))/ 100% calc(1.8*var(--s));
}
.rounded > img:first-child {
  --mask: 
  radial-gradient(calc(var(--s) + var(--g)) at right,#0000 98%,#000) 50%/ 100% calc(1.8*var(--s));
}
.rounded > img:last-child:nth-child(odd) {
  --mask: 
  radial-gradient(calc(var(--s) + var(--g)) at left,#0000 98%,#000) 50%/ 100% calc(1.8*var(--s));
}
.rounded > img:last-child:nth-child(even) {
  --mask: 
  linear-gradient(to right,#0000 var(--s),#000 0),
  radial-gradient(var(--s),#000 98%,#0000) left/calc(2*var(--s)) calc(1.8*var(--s)) repeat-y;
}

body {
  margin: 0;
  background: #ECD078;
}